Apparatus for bulking yarn



Nov. 13, 1962 M. R. LIVINGSTON APPARATUS FOR BULKING YARN Filed July 15,1958 United States Patent Ofifice,

3,063,231 Patented Nov. 13, 1962 The present invention relates to bulkedspun yarn in which a pre-formed continuous filament yarn or equivalentcore is wrapped with discontinuous fibers of staple length with thestaple fiber being substantially uniformly distributed along the lengthof the core and with the staple fiber being buckled to provide a loftyor bulky yarn of the core yarn type. The invention includes the bulkedspun yarn of the core yarn type as well as methods and apparatus for theproduction thereof.

In conventional drafting and spinning, staple fibers are carded into aloose web and then condensed into a roving or sliver'about an inch orless in diameter with the fibers generally extending longitudinally.mally passed beneath rear rolls moving slowly and to forward rollsmoving rapidly so that the roving or sliver is drawn or drafted to anextent corresponding to the difference in velocities between the forwardand rear rolls. Thus, if the forward rolls move at a rate tending toadvance the roving 15 times faster than the rear rolls, the roving iselongated 15 fold. The elongated roving removed from the forward rollsis then twisted and taken up on a bobbin as a spun yarn.

In accordance with the invention, a pre-formed continuous filament yarnor spun yarn intended to constitute a core is passed together with atleast one roving between the forward rolls of a drafting device. Asemployed herein the term roving has reference to a loose strand ofstaple fibers having either a low twist or no twist in which case it issometimes called a sliver. The continuous filament yarn or spun yarnwhich is to constitute the core of the bulked yarn to be produced issupplied under tension so that the core is supplied at a linear speed ofabout 25 to 75 and preferably 40 to 60%, of the peripheral speed of theforward rolls so that the forward rolls are constantly slipping withrespect to the core. In this manner, the staple fiber is caused tobuckle and upon twisting there is produced a composite yarn in which thebuckled staple fibers retain their distorted configurations and arewrapped around the core to form a bulky core yarn or lowered density andincreased loft.

If the continuous core is supplied at a velocity greater than 75% of theperipheral speed of the front rolls substantially no bulking occurs.When the core is fed at 75% of the front roll speed, the yarn isshortened by 25% of the length that would normally be obtained if thecore were fed at the same speed as the front roll surface. This 25%shortening in length results 33% increase in weight per unit length. Ifthe core is fed at only 25% of the peripheral speed of the front rolls,the length is shortened by 75%, resulting in 300% increase in weight perunit length. If the core is fed at less than 25% of the surface speed ofthe fr'ont'rolls, spinning becomes difficult due to excessive breakageapparently resulting from too much twist in the core. Best results, withrespect to bulk and ease of production, are obtained with the core fedat 40 to 60% of the peripheral speed of the front rolls. While thecharacter and length of the staple fibers of the roving have some effecton the 2 rolls with respect to the core may take place without breakingthe core. The exact value of the tension which should not be exceededwill depend upon the nature and denier of the core and can readily bedetermined.

In accordance with another aspect of the invention, a

j plurality of rovings may be employed to supply discontinuous staplelength fiber. However, the product which is produced cannot be untwistedto isolate ends corresponding to separate rovings and, hence, theproduct of the invention is not a plied yarn.

The invention also extends to an apparatus for producing the bulked spuncore yarn, said apparatus including means to supply continuous filamentor spun yarn to the forward rolls of a drafting device at a controlledrate less than the rate at which the forward rolls attempt to accept thecontinuous element so that the continuous This is nordiameter of thecomposite product, i.e. its bulk, the indicated ranges generally producethe best results for any particular staple fiber.

The weighting on the forward rolls is maintained at a low levelsufficient to draft the roving, andv the tension ap l ed t a s su h atpaswtst s few element is constantly slipping with respect to the forwardrolls.

a The invention will be more fully understood from the description whichfollows, taken in conjunction with the accompanying drawing in which:

FIG. 1 is a side elevation diagrammatically illustrating the procedureof the invention together with the equipment employed for carrying outthe process on a schematic basis;

FIG. 2 is an enlarged diagrammatic side elevation illustrating thedrafting device of the invention together with the structural featuresemployed to modify this de vice to produce bulked spun yarn inaccordance with the invention;

FIG. 3 is a diagrammatic plan view illustrating preferred apparatus forcarrying out the invention with the continuous filament supply beingshown in phantom; and

FIG. 4 is a diagrammatic view on an enlarged scale illustrating thenovel bulked spun yarn.

Referring more particularly to FIG. 1, the numeral 10 indicates a bobbinstand or creel in which a plurality of bobbins 11 are mounted inconventional manner to supply rovings 12;. Bobbins 11 are rotatable sothat when the roving 12 is pulled by the drafting device indicatedgenerally by the numeral 13, the bobbins 11 will rotate to unwind therovings 12.

The drafting device 13 is of conventional construction and includes anapron or endless band 14, a pair of control rolls 15 and 16, a weightedback roll which is desirably made of rubber and identified by thenumeral 17,

and a pair of rolls 18 and 19 upon which the endless band or apron 14 ismounted. In advance of the apron 14 is a pair of forward rolls 20 and 21which rotate at a greater velocity than the velocity of the endless band14 or the back roll 17. Thus, the roving 12 is elongated or draftedbetween the back roll 17 and the forward rolls 20 and 21 to attenuatethe same and to parallelize along the length of the roving the staplefiber constituting the same. The drafting can be similarly effectedsubstituting any other conventional equipment for that shown, e.g.double aprons, multi-roll systems, etc.

Mounted on a second creel, rack, or bobbin stand 22 are bobbins 23 whichcarry a continuous core element 24, the continuous core element beingconstituted by a continuous filament yarn or by a previously spun yarn.The core element 24 being a yarn is characterized by its high tensilestrength which permits it to withstand far greater tension than canpossibly be applied to roving 12 without disrupting the same. The coreelement 24 advances from the bobbin 23 through an aperture in the guide25 and then to the forward rolls 20 and 21 of the draftingdevice.13,.the..rate of supply being controlled are driven by anysuitable means whichmay, for examiple, be mechanical or electrical, at arate to provide a peripheral yelocity less than the velocity of theforward 3 rolls 20 and 21. Alternatively, feed rolls 26 and 27 may beinitially driven at a peripheral speed approximately equal to that ofrolls 20 and 21, and means included to continuously retard rolls 26 and27, so that their final peripheral speed is less than that of rolls 20and 21.

By positively driving the feed rolls 26 and 27 at a peripheral speedwhich is less than the peripheral speed of the forward rolls 20 and 21,the core element 24 is advanced by the feed rolls and hencesupplied tothe forward rolls at a rate which is smaller than the rate which theforward rolls attempt to advance the core element. As a result, theforward rolls slip relative to the core element 24 and the staple fibersof the roving 12 are thrust forwardly along the length of the coreelement 24 to cause these staple fibers to be bent or buckled. Thesubsequent twisting serves to lock the buckled fibers in the positionsthey have assumed and the diameter of the composite yarn is effectivelyincreased by the buckled staple fiber to provide a yarn of increasedloft and lowered density.

Only a single bobbin 11 and roving 12 are illustrated in FIG. 1. It willbe understood that a plurality of rovings 12 may be withdrawn fromseparate bobbins and combined together in the same manner as wouldnormally result in the production of a single yarn.

The composite yarn emerging from the forward rolls 20 and 21 and whichcontains buckled staple length fiber associated with a continuous coreelement is then passed through an aperture in the yarn guide 28. Thecomposite yarn is identified by the numeral 29 and it contains acontinuous core constituted by the continuous filament or spun yarn 24associated with the discrete fibers from the drafted roving 12 whichhave been buckled due to the difference between the peripheral speed ofthe forward rolls and the speed at which the core 24 is fed. Thecomposite 29, after passing through the yarn guide 28 is led to a ringspinning device indicated generally by the numeral 31 in which thecomposite 29 is twisted to wrap the discrete fibers from the roving 12around the core element 24 to securely anchor the staple fiber to thecore and to fix and retain the buckled structure of the staple fiber inthe bulked spun product which is produced. The spun composite 29, nowidentified by the numeral 30, is then taken up on the bobbin 33.

As will now be apparent, a conventional spinning frame is modified inaccordance with the invention by the addition of a creel or equivalentmeans to supply continuous filament or spun yarn (the core element 24),and by the addition of means positively to feed the core element at apredetermined constant speed which is smaller than the speed at whichthe forward rolls attempt to receive and advance the core, i.e. smallerthan the peripheral speed of the forward rolls. Additionally, suitableguides accurately to position the roving 12 and the core element 24 maybe included in the structure which is employed.

If each spindle or take up bobbin 33 is fed from separate bobbins 11 andfrom separate bobbins 23 with the various rolls 15, 16, 17, 20, 21, 26and 27 extending the length of the frame, the cost of modifying existingspin- 4 ning frames would be substantial, though it is feasible toeffect such modification.

Preferably, the invention is performed employing apparatus asillustrated in FIG. 3 for the purpose of reducing the cost of modifyingexisting equipment.

Thus, small beams containing the same number of ends as are supplied ona standard spinning frame are prepared. The usual number of ends isabout 240. In this manner, a sheet of yarns or rovings is supplied froma single beam. Referring more particularly to FIG. 3, the rovings 12 aresupplied from the beam 40 as is indicated by the numeral 41. In the samemanner, the core elements 24 are wound on the beam 42.

The core elements 24 supplied from the beam 42 may be supplied to theforward rolls 20 and 21 by the feed rolls 26 and 27 which areillustrated in FIG. 1 and the bulking action previously set forthattained in the same way. In this form of the invention, the coreelements 24 are supplied at a controlled constant speed by directlypredetermining the rate of rotation of the beam 42. Since controlledfeeding is directly accomplished by means of the positive controlledrotation of the beam 42, the feed rolls 26 and 27 may be eliminated.

It will be appreciated that since all of the yarn ends supplied from thebeam 42 (when this beam is driven) or supplied by the feed rolls 26 and27 are simultaneously acted upon in the same manner, all of the bulkedspun yarns which are produced by a given spinning frame will be bulkedto a substantially identical extent.

While various means for positively controlling the rate of supply of thecontinuous core element 24 may be employed, FIGS. 2 and 3 of the drawingillustrate in diagrammatic form an illustrative mechanism foraccomplishing this result. Thus feed rolls 26 and 27 (suitably gearedtogether) or beam 42 are rotated at a uniform rate of speed by means ofthe belt 50 and pulley 51, the rate of rotation being controlled by theconstant speed motor 52.

FIG. 4 diagrammatically illustrates the results which are produced inaccordance with the invention. As will be seen, the core element 24 issubstantially uniformly surrounded and wrapped within staple fiber 35.The staple fiber is buckled as indicated at 36, and the buckle isretained by the twist to provide a composite yarn 37 of increasedeffective diameter. Whereas in a conventional core yarn the staplefibers lie generally fiat against the core and are present in theminimum amount necessary just completely to hide the core, in the novelyarn the staple fibers are present in much greater proportion and theirbuckling produces a bulked product having a diameter many times greaterthan that of either the core or the yarn which would be produced if theroving were drawn and twisted either alone or with a core fed at thesame speed. The product is far more bulky than conventional core yarnshaving the same weight per unit length and composed of the sameproportion of core and staple fibers.

The invention is illustrated in the table which follows, in whichspecific pro-formed yarns are combined with specific rovings in specificmanner to produce bulked spun core yarns:

Table Spinning Frame Final Yarn Weight- Core Feed Set to Produce-Produced Run ing Velocity, No. Core Yarn Roving Forward Percent Rolls,Front Roll Count Twist, Twist, Ounces Speed Including t.p.i. Countt.p.i.

Core

1 100 denier high tenacity 2.0 Hank 3d 2" bright 5 50 15/1 13 7. 5/1 26rayon. cellulose acetate. 2 d0 2.0 Hank 2.5d 2" bright 7 40 8/1 4 3.2/110 cellulose triacetate. 3 100 denier nylon 2.0 Hank 3d 2" dull rayon 618/1 12 12. 6/1 17. 1 4 200 denier cellulose ace- 2.0 Hank 3d 2" bright.3 70 6/1 6 4/1 7.1

tate. cellulose acetate. 5 50 denier nylon do 3 25 40/1 5 10/1 20 It isto be understood that the foregoing detailed description is given merelyby way of illustration and that many variations may be made thereinwithout departing from the spirit of my invention.

Having described my invention, what I desire to secure by Letters Patentis:

1. Apparatus for producing a bulky spun core yarn comprising a rotatableroll, means to supply at least one roving of staple length fibers tosaid roll, means to supply a core to said roll at a constant linearspeed less than the peripheral speed of said roll and to issue from saidroll together with said roving, said roll being frictionally engagedwith said core to such a degree as to cause said roll to slipcontinuously relative to said core, and means to twist the core androving fibers issuing from said roll.

2. Apparatus as recited in claim 1 in which said means to supply saidcore comprises a beam having a plurality of said cores wrappedthereabout, and means to drive said beam at a constant linear speed lessthan the peripheral speed of said roll.

3. Apparatus as recited in claim 1 in which said means to supply atleast one ro-vin-g to said roll includes a beam having a plurality ofrovings wrapped thereabout, and means for feeding a plurality of rovingsto said roll in conjunction with each core.

4. Apparatus for producing a core yarn comprising drafting meanscomprising forward and rear drafting rolls, means to supply at least oneroving to said rear rolls, means to supply a core to said forward rollwhereby said roving being drafted and said core will pass through saidforward roll together so that a composite yarn comprising said core andsaid roving will leave said forward roll, means to supply said core at alimited and constant linear speed less than the peripheral speed of saidforward roll, said forward roll being frictionally engaged with saidcore to such a degree as to cause said forward roll to slip continuouslyrelative to said core, and means to twist the drafted roving and coreissuing from said forward roll.

References Cited in the file of this patent UNITED STATES PATENTS574,941 Richardson Ian. 12, 1897 1,286,311 Heathcock Dec. 18, 19181,608,295 Beswiok Nov. 23, 1926 2,076,270 Harris Apr. 6, 1937 2,076,271Harris Apr. 6, 1937 2,210,883 Chittenden et al. Aug. 13, 1940 2,210,884Chittenden et al. Aug. 13, 1940 2,526,523 Weiss Oct. 17, 1950 2,588,361Cooper Mar. 11, 1952 2,804,745 Foster Sept. 3, 1957 2,880,566 SchlumsApr. 7, 1959 2,901,884 Weinberger et al. Sept. 1, 1959

